It indicates the maximum speed at which the tire can carry a load corresponding to it's load index.
You can find your tires' speed rating and load index listed on the sides of the tires. From there, you can use this guide to understand what those numbers mean: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35
104 T is the 'Load Index' and 'Speed Rating' on modern tires. The load # 104 means each tire can support 900 Kg and the speed rating 'T' means they are good to use up to 118 mph.
The "99Y" on tires indicates the tire's load index and speed rating. The "99" refers to the load index, which signifies that the tire can support a maximum load of 775 kg (1,709 lbs). The "Y" is the speed rating, indicating that the tire is rated for speeds up to 300 km/h (186 mph). This combination helps consumers understand the tire's performance capabilities.
The "106T" on tires indicates the tire's load index and speed rating. The number "106" corresponds to the load index, which means the tire can support a maximum load of 2,109 pounds (or 960 kg) when properly inflated. The letter "T" represents the speed rating, indicating that the tire is rated for a maximum speed of 118 mph (or 190 km/h). This combination helps consumers understand the tire's capacity and performance characteristics.
The 103 is the load index this means that the vehicle is recommended on carrying a maximum capacity of 875 Kilograms. The T is the speed rating, which means that any tyre with a 'T' speed rating is only recommended to go up to a maximum of 118mph.
When your tires squeal at a low speed it can mean a number of things. The tread on your tires may be almost gone or you may have low tire pressure.
Speed Rating
The "116T" on tires indicates the tire's load index and speed rating. The number "116" refers to the load index, which signifies that the tire can support a maximum load of 1,118 pounds (or 507 kg) when properly inflated. The letter "T" denotes the speed rating, indicating that the tire is rated for a maximum speed of 118 mph (or 190 km/h). Together, these ratings help ensure that the tire is suitable for the vehicle's weight and intended speed.
The "104H" on tires indicates the tire's load index and speed rating. The "104" signifies that the tire can support a maximum load of 1,000 kg (2,204 lbs) per tire. The "H" denotes a speed rating, indicating that the tire is rated for speeds up to 210 km/h (130 mph). Together, these ratings help ensure that the tire is suitable for both load capacity and speed performance.
The "112T" on tires refers to the tire's load index and speed rating. The number "112" indicates the maximum load capacity the tire can support, which is approximately 2,540 pounds (or 1,150 kg) per tire. The letter "T" denotes the speed rating, signifying that the tire is rated for a maximum speed of 118 mph (190 km/h). Together, these designations help consumers understand the tire's performance capabilities.
yes, it is not recommended however. The safest thing to do is have all four tires be identical (same brand, tread pattern, speed rating, load index). At least if you are going to mix and match change the tires two at a time.
It is usually expressed the other way: the ratio of the speed of light in a vacuum to the speed of light in a medium. In that case, it is called the "index of refraction".